Sand mold formation

ABSTRACT

Apparatus for forming sand molds comprising an elongate bed. The bed includes adjacent and partially enclosed receptacles for alternately receiving sand. A top cover plate is used for partially further closing the receptacles alternately. The top cover plate is operatively associated with the receptacles for alternately adjusting the configuration of the latter respectively from that configuration for operating on the sand disposed therein to form a mold to that configuration for releasing the mold so formed therein. A pair of opposing yet cooperable pattern plates are shiftably supported for entering together into each of the receptacles respectively, in opposing relation, to compact the sand disposed in the latter. A pair of mold ejectors are also utilized for entering into the receptacles alternately and ejecting the mold so formed in the latter along a pair of parallel endless lines in opposing directions. The elongate bed is reciprocatable longitudinally over a plurality of selected positions such that the pattern plates and ejectors can be aligned properly opposite selected of the receptacles alternately in operative association with the latter.

United States Patent [191 Larkin [451 May 22, 1973 [54] SAND MOLD FORMATION [76] Inventor: Sam Larkin, 254 Beach 140th {57] ABSTRACT Street, B6116 Harbor, Apparatus for forming sand molds comprising an elon- [22] Filed: May 19 1971 gate bed. The bed includes adjacent and partially en- Appl. No.: 144,823

Related US. Application Data Continuation-impart of Ser. No. 114,993, Feb. 12, 1971;

References Cited UNITED STATES PATENTS Powanz ..249/ 172 X Wallwork ..l64/40 X Rearwin et al.... ..l64/213 X Bushnell ..l98l31 AB X Primary Examiner-Robert D. Baldwin Att0meyAbraham Friedman et al.

closed receptacles for alternately receiving sand. A top cover plate is used for partially further closing the receptacles alternately. The top cover plate is operatively associated with the receptacles for alternately adjusting the configuration of the latter respectively from that configuration for operating on the sand disposed therein to form a mold to that configuration for releasing the mold so formed therein. A pair of opposing yet cooperable pattern plates are shiftably supported for entering together into each of the receptacles respectively, in opposing relation, to compact the sand disposed in the latter. A pair of mold ejectors are also utilized for entering into the receptacles alternately and ejecting the mold so formed in the latter along a pair of parallel endless lines in opposing directions. The elongate bed is reciprocatable longitudinally over a plurality of selected positions such that the pattern plates and ejectors can be aligned properly opposite selected of the receptacles alternately in operative association with the latter.

10 (Ilaims, 11 Drawing Figures PATENIE rm 2 21915 SFEET 1 [IF 5 FIG. 2.

SAM LARKIN INVENTOR BYWMM,Z Z M ATTORNEYS mmgnmzems 3,734,153

SHEET 2 [IF 5 SAM LARKJN INVENTOR ATTORNEYS PATENTEDMAYZEIQYS SHEET b 0F 5 FIG.

SAM LARKIN INVENTOR ATTORNEY) PATENTEUIIAYZZ I975 SHEET 5 OF 5 FIG.

SAM LARKIN INVENTOR BY MWMJ ATTORNEYS SAND MOLD FORMATION CROSS-REFERENCE TO RELATED APPLICATIONS This is a continuation-impart of my co-pending U. S. Pat. application Ser. No. 114,993, filed Feb. 12, 1971.

BACKGROUND OF THE INVENTION The present invention relates generally to sand mold formation and more particularly to fully automated apparatus for forming a plurality of sand molds.

Sand molds are generally formed as two sections, one of which is a lower section or drag section and the other of which is the upper section or cope section. Each of these sections are provided with cooperating impressions so that molten metal can be poured between the two sections and cooled to assume the configuration corresponding to the impressions in the opposing cooperable sand mold sections. The procedure is generally time consumming in that it is generally done manually and, therefore, is clearly not suitable for accommodating the great quantative industrial demands currently expected. This manual practice has been modified somewhat and numerous machines have been adapted for more adequately forming a greater number of said molds more rapidly than that of the more primitive manual procedure.

In the more recent sand mold formation machines, sand is deposited into an enclosure and opposing pattern plates are displaced toward one another into the enclosure to compact the sand and impart to the sand on opposite faces of the latter desired impressions corresponding to the impression in the pattern plates respectively. The pattern plates are then removed or retracted out of the enclosure and ejectors are utilized for then entering into the enclosure and ejecting the mold section so formed in the enclosure. It should be clear that the ejected mold section is provided with two opposing faces which are of desired configuration and if disposed opposite another mold section formed in the aforementioned manner, the two faces of each mold section which face one another can be utilized for cooperatively receiving molten metal. The molten metal fills the cavity defined by the opposing faces of the cooperating mold sections and when cooled can be removed from the mold sections in a preferred finished configuration.

It is also clear that a plurality of the mold sections can be successively placed in adjacent relation in linear array and this permits the continuous disposition or pouring of molten metal between each of the cooperating mold sections in a continuous and rapid manner.

In the conventional machine as aforementioned, there is provided means for more expiditiously enhancing the formation of the mold in that there is provided a bed that can be reciprocated between two selected positions such that after a mold is formed in a first enclosure by the opposing pattern plates, the bed can be shifted to a second position upon retraction of the pattern plates from the bed area to permit a first ejector to enter the first enclosure and eject the mold so formed in the first enclosure to a first station. At this point, while the ejector is ejecting the already formed mold in the first enclosure, a second mold is formed by the pattern plates in a second enclosure adjacent the first enclosure on the bed. After the first formed mold is ejected from the first enclosureand the first ejector is retracted away from the bed, and upon retraction of the opposing pattern plates which have operated upon the second enclosure to form the second mold, the bed can then be shifted or reciprocated in the opposite direction to align the second enclosure with a second ejector which is on the opposite side of the pattern plates from that of the first ejector. Thus, the second ejector can enter into the second enclosure and eject the second mold so formed in the latter to a second station. During the ejection of the second mold a third mold is formed in the first enclosure and again the bed can be reciprocated to the first ejector position. This procedure is continuously repeated and it is clear that a great number of sand mold portions can be positioned opposite one another in two parallel linear arrays which can be further operated upon independently.

The aforementioned conventional sand mold formation machine, which although is an improvement in the art, suffers from numerous disadvantages. One of these disadvantages is the fact that the sand-receiving enclosure of the machine, wherein the sand is formed into the respective mold sections, cannot be adjusted for releasing the formed sand mold sections and, therefore, since the sand when compacted adheres to the surfaces of the enclosure in contact therewith, it is very difficult to eject the formed sand mold sections without damaging the latter.

A second disadvantage related to the conventional machine, as aforementioned, is that when the ejector of the machine contacts the finished section to eject the latter, the face of the ejector contacts portions of the impressions formed in the sand and since the weight of the mold is rather heavy, the ejector must exert a great force against the impression in the mold and, therefore, the ejector sometimes damages the latter. Even in the instance where the ejector only peripherally contacts the mold section and is spaced from the formed impression in the latter, the ejector cannot uniformly exert pressure against the entire surface of the mold section in contact therewith and, therefore, as the ejector displaces the mold section, the latter is somewhat distorted during displacement thereof.

A further disadvantage related to the conventional machine, as aforementioned, is the fact that the con ventional machine does ,not permit for the rapid replacement of the patterns to permit the formation of mold sections having different impressions. In this respect, the mold sections as formed each have identical patterns and when it is desired to form other mold' sections with different impressions, the latter cannot be effected without great difficulty in changing the pattern plates of the machine.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a fully automated apparatus for forming a plurality of sand mold sections quickly and reliably.

It is a further object of the present invention to provide apparatus for forming and disposing opposing sand mold sections in a linear array in cooperative relation with one another.

It is still another object of the present invention to provide apparatus for ejecting finished sand mold sections along a pair of parallel endless lines alternately in opposing directions thereby increasing the manufacturing pace, minimizing the effort required to displace a great quantity of mold sections and enhancing the overall efficiency and reliability of the manufacturing process.

It is a further object of the present invention to provide apparatus having adjustable receptacles for first operating on sand to form a mold section and thereafter fully releasing each mold section so formed such that the mold section may be readily ejected selectively without damage thereto.

It is still another object of the present invention to provide apparatus having a plurality of receptacles such that one mold section can be made in one receptacle, while another already formed mold section can be ejected from an adjacent receptacle to speedup the manufacturing process.

It is still a further object of the present invention to provide apparatus having a plurality of receptacles and a plurality of ejectors associated with the receptacles respectively for alternately ejecting molds formed in the latter respectively.

It is another object of the present invention to supply a pressurized fluid to the ejectors for contacting the impression formed in each mold section to aid the ejector eject the formed mold sections from the receptacles.

It is still another object of the present invention to supply a pressurized fluid for cleaning the ejectors simultaneously as the ejectors eject the mold sections formed in the receptacles.

Still another object of the present invention is to provide means for automatically changing patterns so that mold sections may be formed having differing impressions from one another selectively.

BRIEF DESCRIPTION OF THE DRAWINGS With the above and additional objects and advantages in view as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

FIG. 1 is a front elevational view partly in phantom illustrating the relationship of the adjustable receptacles for receiving sand according to the present invention;

FIG. 2 illustrates a plan view of the underside of the top cover portion for the receptacles according to the present invention;

FIGS. 3 and 4 are side elevational views of the pattern compacting members as associated with a sandfilled receptacle and illustrate respectively initial and terminal positions of the opposing patterns;

FIG. 5 is a schematic plan view, partly in crosssection and partly in phantom, illustrating the manner by which the ejectors eject finished mold sections along two parallel endless lines alternately in opposing directions;

FIG. 6 is a front elevational view of the apparatus for depositing sand into a receptacle;

FIG. 7 is a side elevational view, partly in phantom and partly in cross-section illustrating one ejector as associated with a linear array of mold sections, the ejector being in its forward position;

FIG. 8 is a fragmentary perspective view of one face of one ejector;

FIG. 9 is a cross-sectional view taken along the line 9-9 in FIG. 8;

FIG. 10 is a view similar to FIG. 7 illustrating the ejector in its retracted position; and

FIG. 11 is a fragmentary enlarged perspective view of one ejector as associated with a linear array of ejected mold sections.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings and more particularly to FIGS. 1 and 2, the present invention comprises an elongate bed 20. The elongate bed 20 is slidably displaceable horizontally in a fixed bed support 22 (see FIGS. 3 and 4).

Mounted below the elongate bed 20 is a bracket 28. A power cylinder 30 having a piston 32 and fluid carrying channels 34 respectively communicating with the piston 32 is operatively associated with the bracket 28 through the intermediary of a bolt 36 which acts to fix the free end of the piston 32 to the fracket 28. The power cylinder 30 includes a connecting extension 38 or the like for connecting the cylinder 30 to a portion of the fixed frame 39 of the machine or to any other suitably located fixed external source. It is clear therefore, that the cylinder 30 has a fixed relation relative to the frame 39 of the machine and, therefore, as the pis ton 32 is displaced by the fluid carried in the fluid carrying channels 34, the elongate bed 20 is shifted or displaced horizontally as generally shown by the arrow A in FIG. 1.

In the preferred embodiment of the present invention, the elongate bed 20 includes two pairs of opposing side walls, each of the side walls being denoted by the reference characters 40-43 respectively. Each of the side walls 40-43 are pivotally associated with the elongate bed 20 through the intermediary of pins 44 or the like. The walls 40-43 each includes a bracket 46 fixedly mounted thereon. A plurality of hydraulic or pneumatic power cylinders are pivotally utilized for connecting the side walls 40-43 into operative association with the elongate bed 20. In this respect, a cylinder 47 interconnects the side wall 40 to the right-most portion of the bed 20, a pair of cylinders 48 interconnect respectively the side walls 41 and 42 to the middle of the bed 20 and a cylinder-49 interconnects the side wall 43 to the left-most portion of the bed 20 as illustrated in FIG. 1. The elongate bed 20 furthermore includes four pairs of abutment cutouts 45 for operative association with the lowermost portions of the side walls 40-43 proximate the pins 44 respectively. As illustrated in FIG. 1, the side walls 40-43 may be urged toward and away from one another by means of the cylinders 47-49 respectively such that the lowermost pot-- tions of the side walls 40-43 contact the abutment cutouts 45 respectively. In this manner, the abutment cutouts 45 act to limit the pivotal displacement of the side walls 40-43 to operative and inoperative positions respectively which will be discussed further below. It should be understood, of course, that the side walls 40 and 41 and the side walls 42 and 43 cooperatively define, together with the elongate bed 20, two partially open receptacles adjacent one another as will also be further described below.

Depending above the elongate bed 20 is a top cover plate 50 having a hole or opening 51 centrally disposed therein. A pair of fixed guide rods 52, which are fixedly associated with the frame 39 of the apparatus, extend in spaced parallel relation transversely of the bed 20. The guide rods 52 act to guide the displacement of the top cover plate 50 toward and away from the elongate bed 20 in parallel relation with the latter. As illustrated in FIG. 2, the top cover plate 50 is provided with opposite connecting extensions 54 having transverse openings 56 extending therethrough.

A pair of toggle linkage assemblies 58, each having a pair of links 60 and 61, act to support the top cover plate 50 and displace the latter toward and away from the elongate bed 20. The links 60 and 61 are interconnected at 62 as illustrated in FIG. 1. The links 60 are interconnected to the frame 39 pivotally as by pins 64. Similarly, the links 61 are interconnected to the top cover plate 50 pivotally as by pins 66. A power cylinder 68, having fluid carrying channels 70 in communicating relation with a plunger 72 shiftably displaceable in the power cylinder 68, is operatively associated with the toggle linkage assemblies 58 such that the end portion 74 of the plunger 72 is pivotally connected to the leftmost toggle linkage assembly 58 as illustrated in FIG. 1, whereas a connecting extension 76 connected to the power cylinder 68 is pivotally associated with the rightmost toggle linkage assembly 58 as illustrated in FIG. 1

Upon activation of the plunger 72, outwardly of the power cylinder 68, the toggle linkage assemblies 58 assume a triangular-like position as shown in phantom in FIG. 1 to elevate the top cover plate 50 away from the elongate bed 20. In this respect, the power cylinder 68 assumes an elevated position as shown in phantom also in FIG. 1. Similarly, as the plunger 72 of the power cylinder 68 is activated inwardly of the latter, the toggle linkage assemblies 58 assume a position as shown in solid line in FIG. 1 to thereby displace the top cover plate 50 toward the bed 20.

The top cover plate 50 is provided at its underside with a pair of spaced parallel grooves 80 for receiving the upper portions of either the side walls 40 and 41 or 42 and 43 respectively. As discussed above, the abutment cutouts 45 provided in the elongate bed act to restrain or limit the maximum pivotal displacement of the side walls 40-43 respectively and, in this respect, the pivotal displacement of each pair of the side walls 4043 toward one another is limited such that the uppermost portions of the side walls 40-43 respectively are positioned so as to be in operative association with the grooves 80 on the top cover plate 50. In this respect, as the top cover plate is displaced downwardly toward the elongate bed 20, the grooves act to lock the side walls 40 and 41 relative to one another when, depending on the displacement of the bed 20, the latter side walls are disposed immediately therebelow, and similarly, the grooves 80 act to lock the side walls 42 and 43 also relative to one another when the latter side walls are immediately therebelow. The top cover plate in combination with the side walls 40 and 41, therefore, form together with the bed 20, a partially open receptacle into which sand can be disposed through the opening 51 provided in the top cover plate 50.

Reference is now made to FIGS. 3-6, wherein there is illustrated the relationship of the elongate bed 20 with that of the apparatus for further operating upon the sand in the receptacles. A pair of opposing pattern formation assemblies 82 respectively, are provided on the opposite sides of the elongate bed 20. The assemblies 82 include hydraulically or pneumatically controlled pattern plungers 84 respectively for displace ment toward and away from one another laterally of the elongate bed 20. Each of the plungers 84 pivotally supports a plurality of turreted plates 86 provided with selected pattern formation projections differing from one another. The plungers 84 also each include a roller 88 to enhance both the mobility thereof and the support of the turreted pattern plates 86, the roller being displaceable along a platform 90.

The use of the turreted pattern plate arrangement permits selection of specific patterns and rapid changing thereof as demand dictates. In "this respect, certain metals require different molds, due to the content of the former and, thus, a change in pattern may be required periodically. Similarly, different molds are often required simply for choice of design and, thus, periodic change is necessary. As those skilled in the art appreciate, the turrets may be conventionally rotated in their respective plunger supports 91 respectively.

It is important to point out that selected plunger plates 86 are first moved into an initial position, as

shown in FIG. 3, so that cooperatively with the pairs of side walls, there is formed an enclosure into which the sand may be disposed through the top cover plate 50. Thereafter, the plates 86 are shifted to compact the sand and assume positions respectively illustrated in FIG. 4. The plates are then retracted completely free of the bed 20 to permit shifting of the latter as will be clarified below. The sand, of course, is supplied from a bin or hopper 92, the latter which is associated with a pressurized gas supply.

Illustrated in FIG. 5 are a pair of ejector stations 93 disposed respectively on two opposite lateral sides of the pattern formation assemblies 82. The ejector stations 93 include respective ejector plungers 94 (one of which is illustrated in FIG. 7) for displacement laterally of the elongate bed 20 by means of fluid provided in fluid carrying channels 95 communicating with the plungers 94. The plungers 94 each include a pair of respective hollow oppositely facing ejectors 96 for ejecting finished sand molds, M, as formed in the receptacles defined by the side walls 40 and 41 and 42 and 43 respectively, along two parallel endless lines alternately in opposing directions as illustrated by the arrows B in FIG. 5.

As illustrated in FIG. 1, the left-most ejector 96 is horizontally displaceable laterally of the bed 20 and depends downwardly from a support member 97, the latter which is guided along a pair of guide bars 98. A power cylinder 99, either hydraulic or pneumatic, is utilized for shifting the left-most ejector 96, along the bars 98. An identical arrangement is provided for the right-most ejector 96. It should be pointed out that each ejector enclosure is provided with a channel 100 through which a compressed gas may be injected in a manner as will be discussed below.

The operation of the apparatus according to the present invention, and the function and nature of those elements discussed above and not clarified heretofore, will now be discussed. The operation of the apparatus, pursuant to the present invention, may be briefly characterized by first providing an elongate bed 20 with side walls 40-43 respectively to define two adjacent partially open receptacles. The top cover plate 50 is displaced downwardly toward the elongate bed 20, by means of the toggle linkage assemblies 58, to lock two of the side walls immediately therebelow and form a partially open enclosure. The pattern plates 86 are then displaced toward one another to a position illustrated in FIG. 3.

In the position as illustrated in FIG. 3, there is ef fected a fully enclosed station into which sand can be disposed through the opening 51 provided in the top cover plate 50. The pattern plates 86 can then be displaced further toward one another, as illustrated in FIG. 4, to thereby compact the sand and form on the opposite sides of the compacted sand an impression corresponding to the configuration of the pattern plates 86. With the pattern plates 86 in this latter position, there is also formed on the opposite faces of the compacted sand, an open groove (see FIG. 11) by means of groove formation projections (not shown), the open groove communicating with the impression formed by the pattern plates 86 respectively. When the sand is compacted to its preferred degree, the pattern plates 86 are then retracted away from one another, out of the vicinity of the side walls 40 and 41 respectively, and the toggle linkage assemblies 58 respectively are operated upon the the power cylinder 68 so as to displace the links 60 and 61 into the positions as indicated in phantom in FIG. 1.

- With the toggle linkage assemblies 58 in the configuration as illustrated in phantom in FIG. 1, the top cover plate 50 is retracted away from the elongate bed 20 to thereby free the side walls 40 and 41 so that the latter can be urged away from one another into engagement with the abutment cutouts 45 respectively. When the side walls 40 and 41 are in contact with the abutments 45 respectively, the sand mold section that has been formed as discussed above is thereby freed entirely from the confines of the receptacle defined by the side walls 40 and 41 respectively.

The elongate bed 20 may then be shifted to the right to align the just formed sand mold section and the side walls 40 and 41 respectively with the right-most ejector 96. This latter shifting of the elongate bed 20 brings the side walls 42 and 43 immediately below the top cover plate 50. The top cover plate 50 can then descend, and through the intermediary of the locking grooves 80 lock respectively the side walls 42 and 43 into a partially open enclosure as was the case described above for the side walls 40 and 41. The pattern plates 86 may then enter the thus formed partially open enclosure to provide a fully enclosed station into which sand again can be disposed through the opening 51 provided in the top cover plate 50. The pattern plates 86 can then be displaced further toward one another to compact the sand to its selected degree and form the impression therein as discussed above and, thus, form a second mold section.

During the formation of the second mold section within the confines of the side walls 42 and 43, the right-most ejector 96 can be displaced laterally of the bed 20 between the side walls 40 and 41 in a manner illustrated in FIG. 7, to eject the first formed mold section and assume a position as illustrated in phantom in FIG. 5. The displacement of the ejector 96 to eject the first formed mold section can take place either immediately when the side walls 40 and 41 are aligned with the latter or any time during which the second mold section is being formed. The ejector 96 will remain in its latter position without any necessity whatsoever for being retracted and will become operative once again only after the left-most ejector has been activated, and this time will, in a condition of retraction, eject a finished mold section in a manner as illustrated in FIG. 10. The elongate bed 20 is thus, always free to be shifted without retraction of an ejector, and, thus, is free to be shifted to the left as illustrated in solid line in FIG. 5. Thus, the second formed sand mold section between the side walls 42 and 43 is aligned with the left-most ejector 96 and the receptacle defined by the side walls 40 and 41 is now vacant and ready to be operated upon as discussed above. A third mold section is, therefore, capable of being formed in the receptacle defined by the side walls 40 and 41 during which time the left-most ejector 96 is displaced laterally of the elongate bed 20 to eject the second formed mold section. It is clear that this procedure can be repeated continuously to alternately dispose pattern mold sections in two endless linear parallel arrays in opposite directions alternately as each ejector is alternately distended and retracted.

It should be clear that each sand mold section thus formed is in fact only one-half of the sand mold that will be utilized for receiving molten metal. In this respect, as illustrated in FIG. 11, the uppermost surfaces of the adjoining mold sections are provided with open channels 150 defined by the grooves formed by appropriate groove formation projections (not shown) on the pattern plates 86. Thus, molten metal can be poured into these open channels to fill a cavity defined by the opposing impressions formed in the faces of the mold section halves in contact with one another.

It is noteworthy that as the sand mold sections are formed and disposed alternately in opposite directions, in two generally endless parallel linear arrays, the successive cavities defined by the cooperating mold section halves can be successively filled with molten metal continuously.

As discussed above, the ejectors 96 are hollow and each has a pair of oppositely facing open ends 102 to peripherally contact alternately and eject the sand mold sections. As the ejector plunger 94 is displaced toward the formed section, air or similar pressurized fluid is injected through the fluid inlet channel 100 into the appropriate hollow ejector 96. When the appropriate open-end 102 contacts the thus formed mold section, the pressurized air and open-end 102 cooperatively exert a uniform pressure over the entire surface of the thus formed sand mold section in contact therewith and, thus, obviates distortion or other potential damage to the sand mold section as it is ejected, which otherwise may occur when only the open-end 102 contacts the mold section in the absence of pressurized air for filling crevices and other cavities between the ejector 96 and the thus formed section.

As those skilled in the art will readily appreciate, injection or introduction of the pressurized air into a hollow ejector 96 serves another useful purpose in that open withdrawal of the ejector 96 after ejection of the thus formed mold section, the pressurized air acts to blast and cleanse the internal portions of the hollow ejectors 96 from sand grannules or the like that may have collected therein during the ejection stage.

It is noteworthy that the fluid carrying channels associated with each of the power cylinders respectively, all communicate with a pressurized source or sources through the intermediary of conventional valve-like timing devices, as one skilled in the art will readily appreciate and, therefore, further description of hydraulic or pneumatic circuitry is omitted for the sake of clarity. These fluid carrying channels are timed to effect activation of the power cylinders either together or sequentially as may be the case to operate the apparatus according to the present invention selectively as described above.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention.

What is claimed is:

1. Apparatus for forming sand molds, said apparatus comprising an elongate bed, a first pair of adjustable side walls hingedly carried upon and extending laterally of said bed for pivotal movement toward and away from one another, a second pair of adjustable side walls hingedly carried upon and extending laterally of said bed for pivotal movement toward and away from one another, a cover member, means for moving said cover member downwardly toward and upwardly away from said bed for detachable interlocking association with one or the other of said pairs of side walls selectively, said cover member when in interlocking association with one or the other of said pairs of side walls, forming a receptacle passageway having opposing open ends communicating with one another laterally of said bed, said cover member having an aperture, means for introducing sand through said aperture and into said receptacle passageway, a pair of sand compacting pattern plates supported on opposite sides of said bed respectively for movement toward and away from one another laterally of and partially across said bed, a pair of eccentrically depending cantilevered sand mold ejectors supported on opposite sides of one of said pattern plates respectively for alternate movement entirely across and beyond the opposite sides of said bed in a direction parallel to the movement of said pattern plates, and means for reciprocating said bed longitudinally between two extreme endwise positions in a direction transversely of the movement of said pattern plates and ejectors; whereby said first pair of side walls is aligned opposite one of said ejectors and said second pair of side walls is aligned opposite said pattern plates when said bed is in one of said extreme endwise positions, and said first pair of side walls is aligned opposite said pattern plates and said second pair of side walls is aligned opposite the other of said ejectors when said bed is in the other of said extreme endwise positions.

2. Apparatus as claimed in claim 1, wherein each of said cantilevered sand mold ejectors includes a pair of opposite cavities peripherally engageablewith respective sand molds for alternately ejecting respective sand molds in opposing directions.

3. Apparatus as claimed in claim 2, including means for introducing a compressible fluid into the cavities of said ejectors to aid in the ejection of a respective sand mold.

4. Apparatus as claimed in claim 1, wherein said cover member is formed with a pair of spaced parallel grooves for receiving respectively an upper edge portion of each of said side walls in detachable interlocking association.

5. Apparatus as claimed in claim 1, wherein each of said pattern plates is one of a plurality of turret mounted pattern assemblies.

6. Apparatus as claimed in claim 1, including power means operatively associated with each of said side walls for pivotally urging the respective walls of each said pair of side walls toward and away from one another.

7. Apparatus as claimed in claim 1 including guide means for maintaining said cover member generally parallel to said bed as said cover member is displaced toward and away from said bed, said cover member being provided with a pair of spaced openings extending transversely therethrough and said guide means including a pair of spaced rods vertically extending transversely of said bed and through said pair of spaced openings respectively in said cover member.

8. Apparatus as claimed in claim 7 wherein said bed includes abutment means operatively associated with the pivotally mounted side walls for limiting the extent of displacement of the latter to thereby permit positioning of the pivotally mounted side walls in operative association with said cover member.

9. Apparatus as claimed in claim 8 including togglelinkage means operatively associated with said cover member for displacing the latter along said spaced rods toward and away from said bed.

10. Apparatus as claimed in claim 9 including means for displacing said opposing pattern plates toward one another laterally of said bed to an intermediate position for engagement with the side walls associated with a selected one of said receptacles to constitute with the latter said side walls a four-sided enclosure for receiving the sand, further plates for displacing said pattern meansv further toward one another to a terminal position for compacting the sand into a mold, and still further means for fully retracting said pattern plates away from one another and out of the confines of the latter said side walls to permit longitudinal displacement of said bed. i 

1. Apparatus for forming sand molds, said apparatus comprising an elongate bed, a first pair of adjustable side walls hingedly carried upon and extending laterally of said bed for pivotal movement toward and away from one another, a second pair of adjustable side walls hingedly carried upon and extending laterally of said bed for pivotal movement toward and away from one another, a cover member, means for moving said cover member downwardly toward and upwardly away from said bed for detachable interlocking association with one or the other of said pairs of side walls selectively, said cover member when in interlocking association with one or the other of said pairs of side walls, forming a receptacle passageway having opposing open ends communicating with one another laterally of said bed, said cover member having an aperture, means for introducing sand through said aperture and into said receptacle passageway, a pair of sand compacting pattern plates supported on opposite sides of said bed respectively for movement toward and away from one another laterally of and partially across said bed, a pair of eccentrically depending cantilevered sand mold ejectors supported on opposite sides of one of said pattern plates respectively for alternate movement entirely across and beyond the opposite sides of said bed in a direction parallel to the movement of said pattern plates, and means for reciprocating said bed longitudinally between two extreme endwise positions in a direction transversely of the movement of said pattern plates and ejectors; whereby said first pair of side walls is aligned opposite one of said ejectors and said second pair of side walls is aligned opposite said pattern plates when said bed is in one of said extreme endwise positions, and said first pair of side walls is aligned opposite said pattern plates and said second pair of side walls is aligned opposite the other of said ejectors when said bed is in the other of said extreme endwise positions.
 2. Apparatus as claimed in claim 1, wherein each of said cantilevered sand mold ejectors includes a pair of opposite cavities peripherally engageable with respective sand molds for alternately ejecting respective sand molds in opposing directions.
 3. Apparatus as claimed in claim 2, including means for introducing a compressible fluid into the cavities of said ejectors to aid in the ejection of a respective sand mold.
 4. Apparatus as claimed in claim 1, wherein said cover member is formed with a pair of spaced parallel grooves for receiving respectively an upper edge portion of each of said side walls in detachable interlocking association.
 5. Apparatus as claimed in claim 1, wherein each of said pattern plates is one of a plurality of turret mounted pattern assemblies.
 6. Apparatus as claimed in claim 1, including power means operatively associated with each of said side walls for pivotally urging the respective walls of each said pair of side walls toward and away from one another.
 7. Apparatus as claimed in claim 1 including guide means for maintaining said cover member generally parallel to said bed as said cover member is displaced toward and away from said bed, said cover member being provided with a pair of spaced openings extending transversely therethrough and said guide means including a pair of spaced rods vertically extending transversely of said bed and through said pair of spaced openings respectively in said cover member.
 8. Apparatus as claimed in claim 7 wherein said bed includes abutment means operatively associated with the pivotally mounted side walls for limiting the extent of displacement of the latter to thereby permit positioning of the pivotally mounted side walls in operative association with said cover member.
 9. Apparatus as claimed in claim 8 including toggle-linkage means operatively associated with said cover member for displacing the latter along said spaced rods toward and away from said bed.
 10. Apparatus as claimed in claim 9 including means for displacing said opposing pattern plates toward one another laterally of said bed to an intermediate position for engagement with the side walls associated with a selected one of said receptacles to constitute with the latter said side walls a four-sided enclosure for receiving the sand, further plates for displacing said pattern means further toward one another to a terminal position for compacting the sand into a mold, and still further means for fully retracting said pattern plates away from one another and out of the confines of the latter said side walls to permit longitudinal displacement of said bed. 